Houghton

iTrader: (1)

Not quite all. Check post #9. Looks like APi get the coconut for nearest guess(quite apt)

So's any car when it developes a problem.

Rich_B

iTrader: (6)

Sorry to hear of this Dave, but you are not alone - I had an identical experience a year ago with a 99MY on 64k miles: diagnosed with low compression on no.2 cylinder, then oil consumption went very high. Turned out no.2 piston was melted with a large section of the rings completely missing - all put down to MAF failure. I was also disappointed that such a simple component was so fragile and could lead to such damage. Now I'm a bit wary of any 'glitches' in running.

Jay m A

iTrader: (2)

yep, whatever you do, spend £1500 + £70 for a new MAF.

Is £1500 all in including labour? Not sure if Powerstation are doing the STI9 short engines still for £900..

funkyspider

Would a knocklink diagnose a faulty MAF before it started to do this much damage ?

I've got a 2001 bugeye and have been advised not to bother with knocklink as the ECU will cope and retard the ignition as required, but any advice on how to prevent a faulty MAF causing this much damage would be great.

Houghton

iTrader: (1)

From the info on here, it's the MY99 & 00 that have the dodgy MAF sensors, pre and post are more robust. Most (except PS Lewis) would advise a Knocklink if you're modding.

jaytc2003

iTrader: (1)

In two words, directly no, however it will detect detonation that a faulty maf can cause and its always a good idea to see what is happening with the engine (can be mounted discreetly)

Dave M UK

iTrader: (4)

Rich B- what did you do in terms of fixing your engine, new short engine or re bore? how much did you end up paying?

Jay m A- i have tried power station and they said they are unlikely to get any more short engines in so no luck there im affaid.

The new short block will be brought from subaru, just so we know everything is legit and because of the fact that the subaru item will have warrenty.

In regards to the MAF, maybe it was down to it being faulty, maybe not, i will change it just to be sure, but if it was the MAF i had no warning signs like rough engine running or close to stall at junctions, it seems that if the MAF goes then the first thing you will know about it is when a piston melts.
It just seems strange how all imprezas with dodgy MAF's werent recalled by subaru, no one should have a piston melt just because of a lame *** £70 MAF sensor.
On top of all this i am now hearing reports that the actual piston design on the year of my impreza are dodgy anyway and that loads went and were swoped for better ones under the warrenty, all signs point to subaru making a big mistake somewhere along the line and not having the decency to recall obviously due to the money they would lose.

I have been to the garage today to look at the melted piston and scored block,i have 3 options-

1- Smooth out the scores in the cylinder, fit another piston and either hope for the best or sell quick, although i dont have it in me to sell a dodgy impreza with a 'that will do job', i prefer a proper job

2- Rebore the scored cylinder meaning all four clyinders on original block will need to be done also and fit new oversize pistons and associated parts

3- Buy a short block and have that put in with all original parts bolted back on,

In terms of cost number 1 is the cheapest but not the best option, number 2 will end up costing around the same as number 3 after the block has been sent to a machinist and rebored then put back together, and number 3 is going to be the best option but also the most expensive.

The garage is in the process of pricing up the three options but i think i am going for the short block in which case im lookin at around £1500 give or take £300.

I have decided to keep my car for a couple of years and that is why i am swaying toward the new short block option,

Either way i will take it to API for a once over when its done just to make sure its not going to happen again 2 months down the line, apart from that its just a case of holding on and waiting for the bill, guess where my next student loan will be going. definatly not on uni fees and debts,

Jay m A

iTrader: (2)

I would personally get it trailered to API as is, there are other options and they can source recond short blocks with warranty. Or an EJ257 is around £1200 +vat from Lateral IIRC, loads of options - spend that debt wisely!

Rich_B

iTrader: (6)

Dave, due to the amount of piston/ring material that must have been in the engine somewhere, I went for option (3) a new short engine (1200+VAT from Subaru), which as you point out probably isn't much different from option (2). But then add a full gasket set, oil pump, timing belt+tensioner, valve shims, oil etc., brought the parts bill to over 2k. Add the labour, and....ouch! Suffice to say I am looking forward to many years of service from it.
Good luck,
Rich.

hall84

same thing happened to my scoob. melted piston in cylinder 2 with no warning or signs before it happened. all down to a dodgey MAF sensor. cost me around £1200 + £170 for the turbo to b recond. the piston had scored the cylinder and the crank so they had to b polished. while the heads were of they were pressure tested an turns out that number 4 cylinder inlet valves were slightly bent to! so 2 new valves went in. all sorted now and run in but i havent got the confidence i usd to have in it any more.

good luck

j

hall84

oh yea its an MY99!

j

Dave M UK

iTrader: (4)

Spoke to dave from API today, had a long chat and disscused my options.

Going go with the new block and engine rebuild, only problem is im lookin at around 4 weeks.

The price quoted beats my £3100 price from my local garage so thats a good thing.

Dave from API talked me through the process and put my mind at rest and said its probably down to the MAF sensor which makes sense, really decent guy is Dave.

Anyway next move is to get my impreza down to his garage which he can do via a flat bed truck as my car is in bits on a garage floor.

Lots of work, effort and money yet to go but i will feel 100% better knowing that its in the capable hands of the API crew.

Will try and post pics of my melted piston and engine soon, tried the other night but the forum didnt let me copy and paste from my harddrive, anyone know why??

Dave m uk